Excel 2007 does not update chart data
 

I have an Excel 2003 spreadsheet. It calculates several numbers in several
rows. The rows are shown in a simple bar graph. When I open it in Excel 2007,
and I adjust the input, all numbers in all rows are adjusted. But some of the
bars in the graph are not adjusted. The data in the bars are linked to cells
with new values, but the bar shows the old value. Pressing CALC does not
help. Is this a bug in Excel 2007? Or am I doing something wrong?